Image display device and image adjustment method of image display device

ABSTRACT

An image display device capable of performing a shape correction of an image displayed on an image display surface having a corner composed of a plurality of surfaces is provided. The image display device includes: an OSD processing unit that displays identification images respectively corresponding to four sides of an image; an identification image selection unit that accepts an operation of selecting the displayed identification image; a moving operation unit that accepts an operation of moving a node set at a predetermined position of the side corresponding to the selected identification image; and an image processing unit that corrects the shape of the image by moving, based on the operation accepted with the moving operation unit, the node of the side of the image displayed on an image display surface composed of a plurality of surfaces.

CROSS-REFERENCE

This is a Continuation of U.S. patent application Ser. No. 14/041,405filed Sep. 30, 2013, which claims the benefit of Japanese PatentApplication No. 2012-224849 filed Oct. 10, 2012. The disclosures of theprior applications are hereby incorporated by reference herein in theirentireties.

BACKGROUND

1. Technical Field

The present invention relates to an image display device that displaysan image on an image display surface and an image adjustment method ofan image display device.

2. Related Art

Heretofore, projectors have been known in which trapezoidal distortiongenerated when an image is projected onto a projection surface by animage display device (projector) in a tilted state can be corrected by auser's operation. For example, JP-A-2010-250041 discloses that atrapezoidal distortion correction of a projection image is performed bydisplaying four identification images corresponding to corner portionsof four corners of the image and moving, based on a user's operation, acorner portion corresponding to an identification image selected by auser from the four identification images.

When an image display device projects an image, the image is sometimesprojected onto a projection surface having a corner composed of aplurality of surfaces (for example, a projection surface or the likehaving a corner composed of two surfaces). In this case, since the shapeof the projected image is distorted due to an influence of the corner ofthe projection surface, the distortion needs to be corrected. However,the shape of the image projected onto the projection surface having thecorner described above cannot be corrected by simply moving the cornerportions of the four corners of the image as in the related art.Therefore, there is a demand for an image display device including afunction capable of properly correcting the shape of an image projectedonto a projection surface having a corner composed of a plurality ofsurfaces.

SUMMARY

An advantage of some aspects of the invention is to provide an imagedisplay device capable of performing a shape correction of an imagedisplayed on an image display surface having a corner composed of aplurality of surfaces and an image adjustment method of an image displaydevice.

An aspect of the invention is directed to an image display device thatdisplays an image modulated by a light modulation device on an imagedisplay surface, the image display device including: an OSD display unitthat displays at least one of identification images respectivelycorresponding to four sides of the image; an identification imageselection unit that accepts an operation of selecting the displayedidentification image; a moving operation unit that accepts an operationof moving a node set at a predetermined position of the sidecorresponding to the identification image selected with theidentification image selection unit; and an image correction unit thatcorrects the shape of the image by moving, based on the operationaccepted with the moving operation unit, the node of the image displayedon an image display surface composed of a plurality of surfaces.

Another aspect of the invention is directed to an image adjustmentmethod of an image display device that displays an image modulated by alight modulation device on an image display surface, the methodexecuting: displaying at least one of identification images respectivelycorresponding to four sides of the image; accepting an operation ofselecting the displayed identification image; and correcting the shapeof the image by moving, based on a moving operation of a node set at apredetermined position of the side corresponding to the selectedidentification image, the node of the image displayed on an imagedisplay surface composed of a plurality of surfaces.

According to these configurations, the identification imagesrespectively corresponding to the four sides of the image displayed onthe image display surface are displayed, and the shape of the image iscorrected based on the moving operation of the node of the sidecorresponding to the identification image selected from theidentification images. That is, it is possible to perform a shapecorrection on the basis of the node of the side of the image. Therefore,even when the image is displayed on an image display surface having acorner composed of a plurality of surfaces, the shape of the image canbe properly corrected.

Moreover, the user can move the node of the side, while viewing thedisplayed image, to deform (correct) the shape of the image. Therefore,the user can perform the correction while visually grasping how theshape of the image is actually corrected.

In the image display device according to the aspect of the invention, itis preferable that the image display device further includes a modeselection unit that accepts an operation of selecting any one of ahorizontal corner mode in which a shape correction of the imagedisplayed on the image display surface having in the horizontaldirection a corner composed of a plurality of surfaces is performed anda vertical corner mode in which a shape correction of the imagedisplayed on the image display surface having in the vertical directiona corner composed of a plurality of surfaces is performed, and that theOSD display unit displays at least one of the identification imagesrespectively corresponding to two sides of the image in the horizontaldirection when the horizontal corner mode is selected, and displays atleast one of the identification images respectively corresponding to twosides of the image in the vertical direction when the vertical cornermode is selected.

According to the configuration, the identification image of the side(side considered to need to be corrected) of the image on which a shapecorrection can be performed is displayed according to the shape (whethera corner is present in the horizontal direction or the verticaldirection) of the image display surface by the selection of the mode.Due to this, the user can easily recognize which portion (the node ofthe side) the user moves to correct the shape of the image.

In the image display device according to the aspect of the invention, itis preferable that the image display device further includes a guidedisplay unit that displays a guide for indicating at least the node ofthe side of the image displayed on the image display surface. Moreover,the identification images respectively corresponding to corner portionsof four corners of the image may be displayed.

According to the configuration, it is possible to easily recognize theposition of the node set at a predetermined position of the side of theimage. The guide may be a cross-shaped line that divides an image intoquarters, or a graphic such as a circle or a square may be displayed atthe nodes of the sides. Alternatively, a grid-like guide that divides animage into quarters may be displayed to indicate not only the nodes ofthe sides but also the corner portions of the four corners. Since animage correction can be performed also on the corner portions, thecorrection becomes easier.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numbers reference like elements.

FIG. 1 is a block diagram showing the configuration of a projectoraccording to an embodiment.

FIGS. 2A to 2D each show an example of an image projected onto aprojection surface of a two-surface corner, in which FIG. 2A is adiagram for explaining the case of projecting an image onto a projectionsurface where a corner is formed in the horizontal direction and thecorner is convex on a projector side; FIG. 2B is a diagram forexplaining the case of projecting an image onto a projection surfacewhere a corner is formed in the horizontal direction and the corner isconvex in a direction away from the projector; FIG. 2C is a diagram forexplaining the case of projecting an image onto a projection surfacewhere a corner is formed in the vertical direction and the corner isconvex on the projector side; and FIG. 2D is a diagram for explainingthe case of projecting an image onto a projection surface where a corneris formed in the vertical direction and the corner is convex in thedirection away from the projector.

FIG. 3 is a flowchart showing a procedure of a corner-wall shapecorrection.

FIG. 4 is a diagram for explaining a corner setting screen.

FIG. 5A is a diagram for explaining a corner-wall shape selection screenfor horizontal corner; and FIG. 5B is a diagram for explaining a guidedisplayed in an image forming region.

FIGS. 6A and 6B are diagrams each for explaining a corner-wallcorrection adjustment screen for horizontal corner, in which FIG. 6A isa diagram for explaining a screen shown when an identification imageshowing an upper left corner portion is selected; and FIG. 6B is adiagram for explaining a screen shown when an identification imageshowing an upper side is selected.

FIGS. 7A to 7D are diagrams for explaining changes in the image formingregion caused by moving the upper left corner portion when selecting thehorizontal corner; and FIGS. 7E to 7H are diagrams for explainingchanges in the image forming region caused by moving a midpoint of theupper side when selecting the horizontal corner.

FIG. 8A is a diagram for explaining a corner-wall shape selection screenfor vertical corner; and FIG. 8B is a diagram for explaining the guidedisplayed in the image forming region.

FIGS. 9A and 9B are diagrams each for explaining a corner-wallcorrection adjustment screen for vertical corner, in which FIG. 9A is adiagram for explaining a screen shown when an identification imageshowing the upper left corner portion is selected; and FIG. 9B is adiagram for explaining a screen shown when an identification imageshowing a left side is selected.

FIGS. 10A to 10D are diagrams for explaining changes in the imageforming region caused by moving the upper left corner portion whenselecting the vertical corner; and FIGS. 10E to 10H are diagrams forexplaining changes in the image forming region caused by moving themidpoint of the left side when selecting the vertical corner.

FIGS. 11A to 11G are diagrams for explaining a specific procedure whenperforming a shape correction of an image projected onto a projectionsurface of a two-surface corner.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, an image display device and an image adjustment method ofan image display device according to an embodiment of the invention willbe described with reference to the accompanying drawings. In theembodiment, a projector 1 will be described by way of example as animage display device. FIG. 1 is a block diagram showing theconfiguration of the projector 1. As shown in the drawing, the projector1 includes an image signal input unit 11, an image processing unit 12(image correction unit), an OSD processing unit 13, a projection opticalsystem 14, an input operation unit 15, and a control unit 16 thatcontrols these units.

The image signal input unit 11 receives image information (image signal)from an external device 2 such as a personal computer or a DVD player,or an external storage medium 3 such as a USB memory or a compact flash(registered trademark).

The image processing unit 12 executes, based on an image processingprogram previously stored therein, predetermined image processing on theimage information received with the image signal input unit 11. Thepredetermined image processing includes image quality adjustment such asresolution conversion, sharpness adjustment, or luminance adjustment,and a shape correction of an image or the like.

The OSD processing unit 13 performs, based on an instruction of thecontrol unit 16, processing of superimposing an OSD (on-screen display)screen composed of a menu image or message image (OSD image) and thelike on the image information input from the image processing unit 12.The OSD processing unit 13 includes an OSD memory (not shown) to storetherein OSD image information representing a graphic, a font, or thelike for forming the OSD image. When the control unit 16 instructs tosuperimpose an OSD image, the OSD processing unit 13 reads necessary OSDimage information from the OSD memory and executes processing ofsuperimposing the OSD image information on the input image informationat a predetermined position. The image information combined with the OSDimage information is output to a light valve drive unit 24. On the otherhand, when there is no instruction from the control unit 16 tosuperimpose the OSD image, the OSD processing unit 13 outputs the imageinformation input from the image processing unit 12 as it is to thelight valve drive unit 24. The OSD processing unit 13 mainly constitutesthe “OSD display unit” and the “guide display unit” in the appendedclaims.

The projection optical system 14 projects an image onto a projectionsurface S (image display surface) such as a screen. The projectionoptical system 14 has a light source unit 21, a light source drive unit22, a liquid crystal light valve 23 (light modulation device), the lightvalve drive unit 24, and a projection lens 25.

The light source unit 21 is composed of a light source lamp 21 a and areflector 21 b. The light source lamp 21 a is formed of a halogen lamp,a metal halide lamp, a high-pressure mercury lamp, or the like. Thereflector 21 b reflects light emitted from the light source lamp 21 a ina substantially constant direction. The light (illumination light)emitted from the light source unit 21 is separated by a light separationoptical system (not shown) into red (R), green G, and blue (B) colorcomponents and then incident on the liquid crystal light valve 23 (23R,23G, and 23B) for each color. The light source drive unit 22 controls,based on an instruction from the control unit 16, the supply and stop ofpower to the light source unit 21 to switch the light source unit 21 onand off.

The liquid crystal light valve 23 is composed of a liquid crystal panelor the like having liquid crystal sealed between a pair of transparentsubstrates. The liquid crystal light valve 23 is formed with arectangular pixel region 23 a formed of a plurality of pixels arrangedin a matrix. The liquid crystal light valve 23 can apply a drive voltagepixel by pixel to the liquid crystal. The light valve drive unit 24applies a drive voltage according to image information to each pixel ofthe liquid crystal light valve 23 to thereby set the light transmittanceof each pixel.

With the configuration described above, in the projection optical system14, the light emitted from the light source unit 21 transmits throughthe pixel region 23 a of the liquid crystal light valve 23 and thus ismodulated, so that an image according to image information is formed foreach of the color lights. The formed respective color images arecombined pixel by pixel through a light combining optical system (suchas a dichroic prism) (not shown), and projected onto the projectionsurface S through the projection lens 25.

The input operation unit 15 accepts an input operation from a user andincludes a plurality of operating keys for the user to perform variousinstructions on the projector 1. The operating keys include, forexample, a power supply key for switching a power supply on and off, amenu key for performing the display and ending of an OSD menu screen forvarious settings, an enter key for confirming an item selected on theOSD menu screen or the like, four direction keys corresponding to up,down, left, and right directions, and a cancel key for cancelling anoperation or returning to the previous operation (screen). The inputoperation unit 15 mainly constitutes the “identification image selectionunit”, the “moving operation unit”, and the “mode selection unit” in theappended claims.

When the user operates the various operating keys of the input operationunit 15, the input operation unit 15 outputs an operating signalaccording to the contents of the user's operation to the control unit16. In the embodiment, the input operation unit 15 is used as operatingmeans for performing an image shape correction (hereinafter referred toas “corner-wall shape correction function”), which is provided mainly asa function of an OSD menu, in the case of projecting an image onto theprojection surface S having a wall shape and a corner composed of twosurfaces (the projection surface S of a two-surface corner) (describedin detail later).

The input operation unit 15 may be configured using a remote control(not shown) capable of remote operation. In this case, the remotecontrol transmits an operating signal of an infrared ray according tothe contents of the user's operation, and a remote-control signalreceiving unit (not shown) receives the signal and sends it to thecontrol unit 16.

The control unit 16 is composed of a CPU (Central Processing Unit), aROM (Read Only Memory), a RAM (Random Access Memory), and the like. TheCPU is a central processing unit that performs various types ofarithmetic processing. The control unit 16 inputs/outputs signalsto/from each of the units to thereby integrally control the projector 1.The ROM stores control programs and control data that are used by theCPU to perform the various types of arithmetic processing. The controlprograms include the image processing program used in the imageprocessing unit 12. The RAM is used as a working area for the CPU toperform the various types of arithmetic processing.

Next, the outline of image shape correction of the projector 1 in thecase of projecting an image onto the projection surface S of atwo-surface corner will be described with reference to FIGS. 2A to 2D.FIGS. 2A to 2D each show an example of a projection image G projected ina state where the projector 1 is installed in front of the projectionsurface S of a two-surface corner.

FIG. 2A shows an example in the case of projecting an image onto theprojection surface S where a corner is formed in the horizontaldirection and the corner is convex on the projector 1 side. In thiscase, the projection image G, which is displayed in a rectangle if theprojection surface S is planar, is displayed in a shape in which anupper side portion of the image is recessed (concave shape) in adirection toward the center (downward) and a lower side portion thereofis raised (convex shape) in a direction away from the center (downward).Because of this, when an image having a shape distorted inversely withthe projection image G (that is, an image having a shape in which anupper side portion of the image is raised in the direction away from thecenter and a lower side portion thereof is recessed in the directiontoward the center) is set in the pixel region 23 a, the distortion ofthe image can be canceled out to display a rectangular image on theprojection surface S.

The shape of the distortion of the projection image G described above isillustrative only, and this is not limited thereto. The shape of thedistortion of the projection image G varies depending on the angle atwhich the projection surface S is viewed or the angle of projection.That is, depending on the angle at which the projection surface S isviewed or the angle of projection, the image does not always have theshape in which the upper side portion is recessed in the directiontoward the center and the lower side portion is raised in the directionaway from the center even when the image is projected onto theprojection surface S shown in FIG. 2A (the same applies to FIGS. 2B to2D described below).

FIG. 2B shows an example in the case of projecting an image onto theprojection surface S (concave surface) where a corner is formed in thehorizontal direction and the corner is convex in a direction away fromthe projector 1. In this case, the projection image G, which isdisplayed in a rectangle if the projection surface S is planar, isdisplayed in a shape in which the upper side portion of the image israised (convex shape) in a direction away from the center (upward) andthe lower side portion thereof is recessed (concave shape) in adirection toward the center (upward). Because of this, when an imagehaving a shape distorted inversely with the projection image G (that is,an image having a shape in which an upper side portion of the image isrecessed in the direction toward the center and a lower side portionthereof is raised in the direction away from the center) is set in thepixel region 23 a, the distortion of the image can be canceled out todisplay a rectangular image on the projection surface S.

FIG. 2C shows an example in the case of projecting an image onto theprojection surface S where a corner is formed in the vertical directionand the corner is convex on the projector 1 side. In this case, theprojection image G, which is displayed in a rectangle if the projectionsurface S is planar, is displayed in a shape in which both left andright sides of the image are recessed (concave shape) in directionstoward the center. Because of this, when an image having a shapedistorted inversely with the projection image G (that is, an imagehaving a shape in which both left and right sides of the image areraised in directions away from the center) is set in the pixel region 23a, the distortion of the image can be canceled out to display arectangular image on the projection surface S.

FIG. 2D shows an example in the case of projecting an image onto theprojection surface S (concave surface) where a corner is formed in thevertical direction and the corner is convex in the direction away fromthe projector 1. In this case, the projection image G, which isdisplayed in a rectangle if the projection surface S is planar, isdisplayed in a shape in which both the left and right sides of the imageare raised (convex shape) in the directions away from the center.Because of this, when an image having a shape distorted inversely withthe projection image G (that is, an image having a shape in which bothleft and right sides of the image are recessed in the directions towardthe center) is set in the pixel region 23 a, the distortion of the imagecan be canceled out to display a rectangular image on the projectionsurface S.

In the embodiment, a shape correction of an image projected onto theprojection surface S of a two-surface corner described above isperformed using the corner-wall shape correction function (image shapecorrection function) provided on the OSD menu.

Next, with reference to FIGS. 3 to 10H, operations of the projector 1when performing a shape correction (corner-wall shape correction) of animage projected onto the projection surface S of a two-surface cornerwill be described. FIG. 3 is a flowchart showing a procedure of thecorner-wall shape correction. FIGS. 4 to 10H are diagrams for explainingexamples of an operation screen that the user operates when executingthe corner-wall shape correction and an operation method of theoperation screen. FIGS. 4 to 10H each show a screen displayed in thepixel region 23 a of the liquid crystal light valve 23.

First, when the item of “corner-wall shape correction” is selected fromthe OSD menu screen by the user, the control unit 16 of the projector 1instructs the OSD processing unit 13 to display a corner setting screenD01 (refer to FIG. 4) (FIG. 3: S01).

As shown in FIG. 4, on the corner setting screen D01, options to selectfrom two corner types, “horizontal corner 31 (horizontal corner mode)”and “vertical corner 32 (vertical corner mode)”, and operation guidanceinformation 33 are displayed. The “horizontal corner 31 (horizontalcorner mode)” is selected when performing a shape correction of an imageprojected onto the projection surface S where a corner is formed in thehorizontal direction, while the “vertical corner 32 (vertical cornermode)” is selected when performing a shape correction of an imageprojected onto the projection surface S where a corner is formed in thevertical direction. The operation guidance information 33 shows operablekeys in the operating keys of the input operation unit 15 and theoperations thereof.

On the corner setting screen D01, the user selects an item according tothe shape of the projection surface S. That is, when the projectionsurface S has a shape shown in FIG. 2A or 2B, the user selects the“horizontal corner 31”. When the projection surface S has a shape shownin FIG. 2C or 2D, the user selects the “vertical corner 32”.

Next, when the “horizontal corner 31” is selected on the corner settingscreen D01 by the user operation, the control unit 16 instructs the OSDprocessing unit 13 to display a corner-wall shape selection screen forhorizontal corner D02 (refer to FIGS. 5A and 5B) (FIG. 3: S02).

As shown in FIG. 5A, six identification images C (C1 to C6), operationguidance information 41, and a message 42 (“Please select area.”) forthe user are displayed on the corner-wall shape selection screen forhorizontal corner D02. The six identification images C (C1 to C6)correspond to portions whose positions are adjustable on the projectionsurface S where a corner is formed in the horizontal direction, that is,four corners (four corners of an image forming region 23 b (refer toFIG. 5B) in the pixel region 23 a) of an input image, and two sidesthereof (upper and lower sides of the image forming region 23 b) in thehorizontal direction. The position adjustment of each of the upper andlower sides is performed by, specifically, adjusting (moving) theposition of a midpoint (the node in the appended claims) of each of theupper and lower sides.

The identification images C are composed of the identification image C1corresponding to an upper left corner portion of the image formingregion 23 b (input image), the identification image C2 corresponding toa lower left corner portion thereof, the identification image C3corresponding to an upper right corner portion thereof, theidentification image C4 corresponding to a lower right corner portionthereof, the identification image C5 corresponding to the upper sidethereof, and the identification image C6 corresponding to the lower sidethereof. In each of the identification images C1 to C6, an illustrationrepresenting the corresponding corner portion or side is depicted, sothat the user can intuitively understand the correspondences between therespective corner portions and sides of the image forming region 23 band the identification images C1 to C6. Moreover, the outline of one ofthe identification images C1 to C6 is displayed in a color combinationdifferent from that of the other five images, which shows a state wherethe identification image C in the different color combination isselected (FIG. 5A shows a state where the identification image C1 isselected).

As shown in FIG. 5B, when displaying the corner-wall shape selectionscreen D02, a grid-like guide 43 (grid-like guide 43 that divides theimage forming region 23 b into quarters: a grid-like white line in thedrawing) for indicating the corner portions of the four corners and themidpoints of the sides of the pixel region 23 a (the image formingregion 23 b) is displayed in the pixel region 23 a (the image formingregion 23 b). The guide 43 continues to be displayed during displaying acorner-wall correction adjustment screen D03 described later. This is tofacilitate the user's grasp of where the corner or the midpoint of theside as an adjustment target (movement target) is (which portion moveswith an operation) when the user performs various operations describedlater while viewing the image projected onto the projection surface S.It is possible by the user's operation of a predetermined key to displaythe guide 43 with an input image superimposed thereon, display the guide43 alone, or erase the guide 43.

On the corner-wall shape selection screen D02, the user selects theidentification image C corresponding to a position on which the userwants to perform a shape adjustment in the image projected onto theprojection surface S. For example, when the user wants to adjust theposition of the upper right corner portion of the image projected ontothe projection surface S, the user selects the identification image C3.For example, when the user wants to adjust the position of the upperside of the image projected onto the projection surface S, the userselects the identification image C5.

Next, when the desired identification image C is selected (entered) onthe corner-wall shape selection screen D02 by the user, the control unit16 instructs the OSD processing unit 13 to display the corner-wallcorrection adjustment screen for horizontal corner D03 (refer to FIGS.6A and 6B) corresponding to the selected identification image C (FIG. 3:S03).

FIG. 6A is the corner-wall correction adjustment screen D03 shown whenthe identification image C1 is selected by the user, while FIG. 6B isthe corner-wall correction adjustment screen D03 shown when theidentification image C5 is selected by the user. On the corner-wallcorrection adjustment screen D03, an enlarged image 51 obtained byenlarging the identification image C selected on the corner-wall shapeselection screen D02, operation guidance information 52, and a message53 (“Please carry out adjustment.”) for the user are displayed.

Triangular direction marks D representing up, down, left, and rightdirections are added to the enlarged image 51, which shows that thecorner portion or the midpoint of the side corresponding to the enlargedidentification image C is movable (adjustable in position) in the up,down, left, and right directions. That is, FIG. 6A shows that the upperleft corner portion of the image forming region 23 b (input image) ismovable in the up, down, left, and right directions, while FIG. 6B showsthat the midpoint of the upper side of the image forming region 23 b(input image) is movable in the up, down, left, and right directions(the same applies to the corner-wall correction adjustment screen D03corresponding to each of the other identification images C).

In a state where the corner-wall correction adjustment screen D03 isdisplayed, when the user operates the direction keys to thereby adjustthe positions of the corner portions of the four corners or themidpoints of the upper and lower sides, the control unit 16 instructsthe image processing unit 12 to execute the shape correction of theimage forming region 23 b according to the user operation (FIG. 3: S04).

With reference to FIGS. 7A to 7H, an example of change in shape of theimage forming region 23 b according to the user operation on thecorner-wall correction adjustment screen for horizontal corner D03 willbe described as a specific example of the processing in S04. FIGS. 7A to7D show how the shape of the image forming region 23 b (a white portionin the drawing) changes when a key operation is performed by the user inthe state where the corner-wall correction adjustment screen D03 (referto FIG. 6A) corresponding to the upper left corner portion (theidentification image C1) is displayed.

For example, when the right direction key is operated in the state ofFIG. 7A, the upper left corner portion of the image forming region 23 bis moved to the right. With the movement of this corner portion, twosides connected to this corner portion (that is, a side connecting theupper left corner portion with the lower left corner portion and a sideconnecting the upper left corner portion with the midpoint of the upperside) are moved by a predetermined amount. Due to this, the imageforming region 23 b is deformed into a shape shown in FIG. 7B.

When the down direction key is operated in the state of FIG. 7A, theupper left corner portion of the image forming region 23 b is moveddownward. With the movement of this corner portion, two sides connectedto this corner portion are moved by a predetermined amount. Due to this,the image forming region 23 b is deformed into a shape shown in FIG. 7C.

When the down direction key is operated in the state of FIG. 7B, theupper left corner portion of the image forming region 23 b is moveddownward. With the movement of this corner portion, two sides connectedto this corner portion are moved by a predetermined amount. Due to this,the image forming region 23 b is deformed into a shape shown in FIG. 7D.Similarly, when the right direction key is operated in the state of FIG.7C, the image forming region 23 b is deformed into a shape shown in FIG.7D.

The corner portions of the image forming region 23 b cannot be moved tothe outside of the pixel region 23 a. Therefore, when the corner portionis located on the outer edge (on the border) of the pixel region 23 a,that is, at the limit of a movable range, the control unit 16 ignoresthe key operation in directions toward the outside of the pixel region23 a (the same applies to the midpoints of the sides).

On the other hand, FIGS. 7E to 7H show how the shape of the imageforming region 23 b changes when a key operation is performed by theuser in the state where the corner-wall correction adjustment screen D03(refer to FIG. 6B) corresponding to the upper side (the identificationimage C5) is displayed.

For example, when the down direction key is operated in the state ofFIG. 7E, the midpoint of the upper side of the image forming region 23 bis moved downward. With the movement of this midpoint, the upper side(that is, a side connecting the upper left corner portion with themidpoint of the upper side and a side connecting the upper right cornerportion with the midpoint of the upper side) is deformed, so that theimage forming region 23 b is deformed into a shape shown in FIG. 7F.

When the left direction key is operated in the state of FIG. 7F, themidpoint of the upper side of the image forming region 23 b is moved tothe left. With the movement of this midpoint, the upper side isdeformed, so that the image forming region 23 b is deformed into a shapeshown in FIG. 7G.

When the right direction key is operated in the state of FIG. 7F, themidpoint of the upper side of the image forming region 23 b is moved tothe right. With the movement of this midpoint, the upper side isdeformed, so that the image forming region 23 b is deformed into a shapeshown in FIG. 7H.

When the left or right direction key is operated in the state of FIG.7E, the shape of the image forming region 23 b does not change. However,with the rightward or leftward movement of the midpoint of the upperside of the image forming region 23 b, the image displayed in the imageforming region 23 b is expanded or contracted by a predetermined amount.

In the above description, the case of operating the upper left cornerportion or the midpoint of the upper side has been described. However,the shape change is performed by a similar method (algorithm) also inthe case of operating the other corner portions or sides (midpoints).

Next, the case where the “vertical corner 32” is selected on the cornersetting screen D01 (refer to FIG. 4) by the user operation will bedescribed. When the “vertical corner 32” is selected by the useroperation, the control unit 16 instructs the OSD processing unit 13 todisplay a corner-wall shape selection screen for vertical corner D04(refer to FIGS. 8A and 8B) (FIG. 3: S05). The description of portionssimilar to those when selecting the horizontal corner 31 described aboveis omitted.

As shown in FIG. 8A, six identification images C (C7 to C12), theoperation guidance information 41, and the message 42 (“Please selectarea.”) for the user are displayed on the corner-wall shape selectionscreen for vertical corner D04. The six identification images C (C7 toC12) correspond to portions whose positions are adjustable on theprojection surface S where a corner is formed in the vertical direction,that is, four corners of an input image (four corners of the imageforming region 23 b) and two sides thereof (left and right sides of theimage forming region 23 b) in the vertical direction.

The identification images C are composed of the identification image C7corresponding to the upper left corner portion of the image formingregion 23 b (input image), the identification image C8 corresponding tothe left side thereof, the identification image C9 corresponding to thelower left corner portion thereof, the identification image C10corresponding to the upper right corner portion thereof, theidentification image C11 corresponding to the right side thereof, andthe identification image C12 corresponding to the lower right cornerportion thereof. When displaying the corner-wall shape selection screenD04, the grid-like guide 43 for indicating the corner portions of thefour corners and the midpoints of the sides is displayed in the pixelregion 23 a (the image forming region 23 b) (FIG. 7B).

Next, when the desired identification image C is selected (entered) onthe corner-wall shape selection screen D04 by the user, the control unit16 instructs the OSD processing unit 13 to display a corner-wallcorrection adjustment screen for vertical corner D05 (refer to FIGS. 9Aand 9B) corresponding to the selected identification image C (FIG. 3:S06).

FIG. 9A is the corner-wall correction adjustment screen D05 shown whenthe identification image C7 is selected by the user. Although the screenconfiguration is similar to that of the corner-wall correctionadjustment screen for horizontal corner D03 shown in FIG. 6A, a changein shape of the image forming region 23 b associated with a positionadjustment of the corner portion is different (described in detaillater). FIG. 9B is the corner-wall correction adjustment screen D05shown when the identification image C8 is selected by the user. Thedirection marks D representing that the midpoint of the left side of theimage forming region 23 b (input image) is movable in the up, down,left, and right directions are added to the enlarged image 51 on thescreen.

In a state where the corner-wall correction adjustment screen D05 isdisplayed, when the user operates the direction keys to thereby adjustthe positions of the corner portions of the four corners or themidpoints of the left and right sides, the control unit 16 instructs theimage processing unit 12 to execute the shape correction of the imageforming region 23 b according to the user operation (FIG. 3: S07).

With reference to FIGS. 10A to 10H, an example of change in shape of theimage forming region 23 b according to the user operation on thecorner-wall correction adjustment screen for vertical corner D05 will bedescribed as a specific example of the processing in S07. FIGS. 10A to10D show how the shape of the image forming region 23 b changes when akey operation is performed by the user in the state where thecorner-wall correction adjustment screen D05 (refer to FIG. 9A)corresponding to the upper left corner portion (the identification imageC7) is displayed.

For example, when the right direction key is operated in the state ofFIG. 10A, the upper left corner portion of the image forming region 23 bis moved to the right. With the movement of this corner portion, twosides connected to this corner portion (that is, a side connecting theupper left corner portion with the upper right corner portion and a sideconnecting the upper left corner portion with the midpoint of the leftside) are moved by a predetermined amount. Due to this, the imageforming region 23 b is deformed into a shape shown in FIG. 10B.

When the down direction key is operated in the state of FIG. 10A, theupper left corner portion of the image forming region 23 b is moveddownward. With the movement of this corner portion, two sides connectedto this corner portion are moved by a predetermined amount. Due to this,the image forming region 23 b is deformed into a shape shown in FIG.10C.

When the down direction key is operated in the state of FIG. 10B, theupper left corner portion of the image forming region 23 b is moveddownward. With the movement of this corner portion, two sides connectedto this corner portion are moved by a predetermined amount. Due to this,the image forming region 23 b is deformed into a shape shown in FIG.10D. Similarly, when the right direction key is operated in the state ofFIG. 10C, the image forming region 23 b is deformed into a shape shownin FIG. 10D.

On the other hand, FIGS. 10E to 10H show how the shape of the imageforming region 23 b changes when a key operation is performed by theuser in the state where the corner-wall correction adjustment screen D05(refer to FIG. 9B) corresponding to the left side (the identificationimage C7) is displayed.

For example, when the right direction key is operated in the state ofFIG. 10E, the midpoint of the left side of the image forming region 23 bis moved to the right. With the movement of this midpoint, the left side(that is, a side connecting the upper left corner portion with themidpoint of the left side and a side connecting the lower left cornerportion with the midpoint of the left side) is deformed, so that theimage forming region 23 b is deformed into a shape shown in FIG. 10F.

When the up direction key is operated in the state of FIG. 10F, themidpoint of the left side of the image forming region 23 b is movedupward. With the movement of this midpoint, the left side is deformed,so that the image forming region 23 b is deformed into a shape shown inFIG. 10G.

When the down direction key is operated in the state of FIG. 10F, themidpoint of the left side of the image forming region 23 b is moveddownward. With the movement of this midpoint, the left side is deformed,so that the image forming region 23 b is deformed into a shape shown inFIG. 10H.

When the up or down direction key is operated in the state of FIG. 10E,the shape of the image forming region 23 b does not change. However,with the upward or downward movement of the midpoint of the left side ofthe image forming region 23 b, the image displayed in the image formingregion 23 b is expanded or contracted by a predetermined amount.

Next, with reference to FIGS. 11A to 11G, a specific procedure whenperforming a shape correction of an image projected onto the projectionsurface S of a two-surface corner will be described. Herein, a case willbe described in which an image is projected onto the projection surfaceS where a corner is formed in the horizontal direction and the corner isconvex on the projector 1 side. In the description of FIGS. 11A to 11G,the corner-wall shape selection screen for horizontal corner D02 and thecorner-wall correction adjustment screen D03 are displayed, forconvenience sake, at positions (on the right side in the drawing)outside the projection image G. Actually, however, the screens D02 andD03 are displayed by being superimposed on the projection image G.Arrows A in the drawings are shown for explaining the moving directionof the corner portion or the midpoint of the side of the projectionimage G, and not displayed actually.

First, when the user selects the “horizontal corner 31” on the cornersetting screen D01 (refer to FIG. 4), the corner-wall shape selectionscreen for horizontal corner D02 is displayed superimposed on theprojection image G as shown in FIG. 11A. In this state, the user selectsthe identification image C1 corresponding to the upper left cornerportion. Then, when the enter key is operated by the user, the projector1 (the control unit 16) displays the corner-wall correction adjustmentscreen D03 (the corner-wall correction adjustment screen D03 with whichthe position of the upper left corner portion is adjustable)corresponding to the identification image C1 by superimposing on theprojection image G (FIG. 11B).

In this state, the user moves the upper left corner portion by operatingthe direction key. In this case, the user operates the down directionkey to move the upper left corner portion of the projection image G to aposition at which the upper left corner portion is parallel to themidpoint of the upper side, so that the shape of the projection image Gis adjusted to that shown in FIG. 11C.

Next, the user selects on the corner-wall shape selection screen D02 theidentification image C3 corresponding to the upper right corner portion.Then, when the enter key is operated by the user, the projector 1 (thecontrol unit 16) displays the corner-wall correction adjustment screenD03 (the corner-wall correction adjustment screen D03 with which theposition of the upper right corner portion is adjustable) correspondingto the identification image C3 by superimposing on the projection imageG (FIG. 11D).

In this state, the user moves the upper right corner portion byoperating the direction key. In this case, the user operates the downdirection key to move the upper right corner portion of the projectionimage G to a position at which the upper right corner portion isparallel to the midpoint of the upper side, so that the shape of theprojection image G is adjusted to that shown in FIG. 10E.

Next, the user selects on the corner-wall shape selection screen D02 theidentification image C6 corresponding to the lower side. Then, when theenter key is operated by the user, the projector 1 (the control unit 16)displays the corner-wall correction adjustment screen D03 (thecorner-wall correction adjustment screen D03 with which the position ofthe midpoint of the lower side is adjustable) corresponding to theidentification image C6 by superimposing on the projection image G (FIG.11F).

In this state, the user moves the midpoint of the lower side byoperating the direction key. In this case, the user operates the updirection key to move the midpoint of the lower side of the projectionimage G to a position at which the midpoint of the lower side isparallel to the lower left corner portion and the lower right cornerportion, so that the shape of the projection image G is adjusted to thatshown in FIG. 11G. Through the operations described above, thedistortion of the projection image G projected onto the projectionsurface S of a two-surface corner can be eliminated.

According to the embodiment as has been described above, theidentification images C respectively corresponding to the cornerportions of the four corners of an image displayed on the projectionsurface S and the four sides of the image are displayed, and the shapeof the image is corrected based on the moving operation of the cornerportion or the midpoint (node) of the side corresponding to theidentification image C selected from the identification images C. Thatis, it is possible to perform not only a shape correction of the cornerportion of the image but also a shape correction on the basis of themidpoint of the side of the image. Therefore, even when the image isdisplayed on the projection surface S of a two-surface corner, the shapeof the image can be properly corrected.

Moreover, the user can move the corner portion or the midpoint of theside, while viewing the displayed image, to deform (correct) the shapeof the image. Therefore, the user can perform the correction whilevisually grasping how the shape of the image is actually corrected.

Although, in the embodiment, the shape of the guide 43 is grid-like,this is not limited thereto. For example, the guide 43 may be across-shaped line that divides an image into quarters, or a graphic suchas a circle or a square may be displayed at the corner portions or themidpoints of the sides.

Although, in the embodiment, two screens, the corner-wall shapeselection screen for horizontal corner D02 and the corner-wall shapeselection screen for vertical corner D04, are disposed, these may be puttogether as one screen. In this case, it is sufficient to display theidentification images C so as to be distinguishable between selectableand non-selectable ones according to the selected corner type. Forexample, when the horizontal corner 31 is selected, the identificationimages C corresponding to the left and right sides are displayed in grayor the like so as to be non-selectable. When the vertical corner 32 isselected, the identification images C corresponding to the upper andlower sides are displayed in gray or the like so as to benon-selectable.

Although, in the embodiment, a case has been described in which an imageis projected onto the projection surface S having a corner composed oftwo surfaces (the projection surface S of a two-surface corner), this isnot limited thereto. The invention can be applied also to the case ofprojecting an image onto a projection surface S having a corner composedof a plurality of surfaces (three or more surfaces).

Although, in the embodiment, the light source unit 21 is composed of thelight source lamp 21 a of a discharge type, a solid-state light sourcesuch as a laser or an LED may be used.

Although, in the embodiment, a transmissive liquid crystal displaysystem is adopted as the display system of the projector 1, any displayprinciple, such as a reflective liquid crystal display system or a DLP(Digital Light Processing) (registered trademark) system, is possible.Moreover, in addition to the projector 1, the invention may be appliedto a rear projector integrally including a transmissive screen, and animage display device such as a liquid crystal display.

Each function (each processing) of the projector 1 shown in theembodiment can be provided as a program. Moreover, the program can bestored in various recording media (a CD-ROM, a flash memory, and thelike) to provide the same. That is, a program for causing a computer tofunction as each constituent component of the projector 1, and arecording medium having the program recorded thereon are also includedin the scope of the appended claims.

Regardless of the embodiment described above, the device configuration,processing step, and the like of the projector 1 can be appropriatelymodified within a range not departing from the gist of the invention.

What is claimed is:
 1. An image display device that displays an imagemodulated by a light modulation device on an image display surface,comprising: an identification image selector that accepts an operationof selecting a displayed identification image corresponding to one offour sides of the image; a moving operator that accepts an operation ofmoving anode set at a predetermined position of the side correspondingto the identification image selected with the identification imageselector; and a processor executing a program configured to: display thedisplayed identification image corresponding to one of four sides of theimage; and correct a shape of the image by moving, based on theoperation accepted with the moving operator, the node of the imagedisplayed on an image display surface composed of a plurality ofsurfaces.
 2. The image display device according to claim 1, furthercomprising: a mode selector that accepts an operation of selecting ahorizontal corner mode in which the shape of the image is corrected whenthe plurality of surfaces of the image display surface form a horizontalcorner, or a vertical corner mode in which the shape of the image iscorrected when the plurality of surfaces of the image display surfaceform a vertical corner, wherein the program is further configured to:display an identification image corresponding to one of two sides of theimage in a horizontal direction when the horizontal corner mode isselected; and display an identification image corresponding to one oftwo sides of the image in a vertical direction when the vertical cornermode is selected.
 3. The image display device according to claim 1,wherein the program is further configured to: display a guide forindicating the node of the image displayed on the image display surface.4. The image display device according to claim 1, wherein: the programis further configured to display identification images respectivelycorresponding to corner portions of four corners of the image, theidentification image selector accepts an operation of selecting anidentification image corresponding to the corner portion displayed bythe program, and the moving operator accepts an operation of moving anode set at a predetermined position of the identification imagecorresponding to the corner portion selected with the identificationimage selector.
 5. An image adjustment method of an image display devicethat displays an image modulated by a light modulation device on animage display surface, the method executing: displaying anidentification image corresponding to one of four sides of the imageusing the image display device; accepting an operation of selecting thedisplayed identification image; displaying a node set at a predeterminedposition of the side corresponding to the selected identification imageon an image display surface composed of a plurality of surfaces;accepting a moving operation of the node; and displaying a movement ofthe node and a correction in a shape of the image based on the movingoperation of the node.